Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds the aggregation shape (one grouping column, outcomes per group), which is useful, but says nothing about result size, pagination, or limits for larger periods.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single eleven-word sentence with no filler, and the core resource is front-loaded. It is arguably under-specified rather than verbose, so it errs on the terse side but wastes nothing.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With five parameters, no output schema, and real defaults (30-day window, mode fallback), the description only hints at the response via 'each group with its outcomes'. It leaves the concrete return shape unexplained, though the schema covers input semantics fully.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema fully documents the date range, mode, group_by, and project_id semantics. The phrase 'grouped by one column' loosely echoes group_by but adds no syntax or constraint detail beyond the schema's 'Required: project, api_key, method, transport, format or mode.'

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a concrete operation and resource: aggregating a period's checks grouped by one dimension, with per-group outcomes. It is clear in isolation, but it never distinguishes itself from the similar sibling get_failure_breakdown or from get_summary, so an agent gets no help choosing among them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as get_failure_breakdown, get_summary, or get_timeseries. The agent must infer the selection criteria entirely from the sibling names.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.